DERIVATIVE INSTRUMENTS - Summary of Characteristics of Interest Rate Swaps (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2026	Dec. 31, 2025
Interest rate swaps, at fair value
Derivative [Line Items]
Current notional	$ 73,767,398	$ 63,192,398
Weighted Average Pay Rate	3.20%	3.15%
Weighted Average Receive Rate	3.73%	3.92%
Weighted average years to maturity	4 years 1 month 20 days	4 years 2 months 23 days
Interest rate swaps, at fair value \| Federal funds index swap
Derivative [Line Items]
Notional amount, percentage	2.00%	2.00%
Interest rate swaps, at fair value \| Secured Overnight Financing Rate
Derivative [Line Items]
Notional amount, percentage	98.00%	98.00%
Interest rate swaps, at fair value \| 0 - 3 years
Derivative [Line Items]
Minimum maturity period	0 years	0 years
Maximum maturity period	3 years	3 years
Current notional	$ 35,205,637	$ 29,577,637
Weighted Average Pay Rate	3.40%	3.55%
Weighted Average Receive Rate	3.69%	3.88%
Weighted average years to maturity	1 year 3 months 14 days	1 year 4 months 9 days
Interest rate swaps, at fair value \| 3 - 6 years
Derivative [Line Items]
Minimum maturity period	3 years	3 years
Maximum maturity period	6 years	6 years
Current notional	$ 18,864,704	$ 14,646,904
Weighted Average Pay Rate	2.73%	2.67%
Weighted Average Receive Rate	3.81%	3.99%
Weighted average years to maturity	4 years 6 months 25 days	4 years 6 months 14 days
Interest rate swaps, at fair value \| 6 - 10 years
Derivative [Line Items]
Minimum maturity period	6 years	6 years
Maximum maturity period	10 years	10 years
Current notional	$ 18,106,627	$ 17,018,427
Weighted Average Pay Rate	3.39%	3.03%
Weighted Average Receive Rate	3.72%	3.90%
Weighted average years to maturity	7 years 8 months 8 days	7 years 3 months
Interest rate swaps, at fair value \| Greater than 10 years
Derivative [Line Items]
Minimum maturity period	10 years	10 years
Current notional	$ 1,590,430	$ 1,949,430
Weighted Average Pay Rate	3.34%	3.34%
Weighted Average Receive Rate	3.75%	3.92%
Weighted average years to maturity	21 years 8 months 26 days	22 years 7 days
Forward starting pay fixed swaps
Derivative [Line Items]
Current notional	$ 0	$ 1,500,000